package com.hmdp.utils;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

/**
 * Created by Lenovo
 * DATA:2023/11/7
 **/
@Component
public class RedisIdWorker {
    //开始时间戳
    private static  final long BEGIN_TIMESTAMP = 1640995200L;
    //序列号的位数。
    private static final int COUNT_BITS = 32;
    private StringRedisTemplate stringRedisTemplate;

    public RedisIdWorker(StringRedisTemplate stringRedisTemplate) {
        this.stringRedisTemplate = stringRedisTemplate;
    }

    public long nextId(String keyPrefix){
        //1.生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);
        long timestamp = nowSecond - BEGIN_TIMESTAMP;


        //2.生成序列号
        //2.1获取当前的日期，精确到天。
        String date = now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        //2.2自增长
        Long increment = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + date);

        //3.拼接并返回

        return timestamp << COUNT_BITS | increment;
    }

    public static void main(String[] args) {
        LocalDateTime time = LocalDateTime.of(2022, 1, 1, 0, 0);
        long second=time.toEpochSecond(ZoneOffset.UTC);
        System.out.println("second = " + second);

    }
}
